Complete the clinical evaluation of the reactivity and antigenicity of a pneumococcal polyvalent vaccine containing polysaccharide types 1, 3, 6, 7, 14, 18, 19, and 23, which were administered to selected age groups in the following sequence: 3-7 years, 1-2 years, and infants less than 12 months of age using two dosage levels (25 ug and 50 ug each type) in at least 20 volunteers per age group. Clinically evaluate the pneumococcal polyvalent vaccine in infants aged 3, 7, and 12 months. Administer a booster immunization at the appropriate time in order to obtain maximal antibody response. Sera should be obtained from vaccinees before and at 1, 6, and 12 months following immunization. An assessment of antigenicity should be performed by the Contractor using the indirect hemagglutination test. Aliquots from the same battery of sera should be quantitated for type specific antibody by the radioimmunoassay at a central serologic laboratory designated by the Project Officer.